Stats Midterm Practice Test

Create an illustration of a classroom setting with high school students taking a statistics exam, books and papers scattered, a clock on the wall showing time ticking down, and a teacher observing. The atmosphere should be focused and slightly tense, illustrating the pressure of exam preparation.

Stats Midterm Practice Test

This quiz is designed for students preparing for their statistics midterm exam. It covers essential concepts and questions related to statistics, sampling, data interpretation, and measures of central tendency.

56 carefully crafted questions
Multiple-choice format for easy answering
Covers a wide range of statistical topics

56 Questions14 MinutesCreated by StudyingStar57

A researcher is interested in the effect of amount of sleep on high school students’ exam scores. A group of 75 high school boys agree to participate in the study. The boys are _____.

A statistic

A variable

A parameter

A sample

When sample differs from the population there is a systematic difference between groups

True

False - sampling error due to random influence may produce unsystematic group difference

Research measurements are made using specific procedures that define constructs

True

False

Variables that cannot be measured directly cannot be studied scientifically

True

False - constructs (interval states) can only be observed indirectly, but can be operationally measured

A study assesses the optimal size (number of other members) for study groups. The variable size of group is _____.

Discrete and interval

Continuous and ordinal

Discrete and ratio

Continuous and interval

Researchers observed that students’ exam scores were higher the more sleep they had the night before. This study is _____.

Descriptive

Experimental comparison of groups

Non-experimental group comparison

Correlational

All research methods have an independent variable

True

False - correlational methods do not need an independent variable

All research methods can show cause-and-effect relationships

True

False - only experiments control the influence of participants and environmental variables

�X2 + 47 instructs you to _____.

Square each score and add 47 to it, then sum those squares

Square each score add up the squared scores, then add 47 to that sum

Add 47 to each score, square the result, and sum those numbers

Add up the scores, square that sum, and add 47 to it

�X2 = (∑X)2

True

False - when the operations are performed in a different order, the results will be different

Use the frequency distribution table to determine how many subjects were in the study.

Impossible to determine

The proportion of scores in the lowest category was p=3

True

False - a proportion is a fractional part; 3/10 = .3

A grouped frequency distribution table has categories 0–9, 10–19, 20–29, and 30–39. What is the width of the interval 20–29?

9 points

9.5 points

10 points (29.5-19.5 = 10)

10.5 points

You can determine how many individuals had each score from a frequency distribution table

True

False

You can determine how many individuals had each score from a grouped frequency distribution

True

False - only the number of individuals in the class interval is available once the scores are grouped

What is the shape of this distribution

Symmetrical

Negatively skewed

Positively skewed

Discrete

It would be correct to use a histogram to graph parental marital status data from a treatment center for children

True

False - nominal variable, requires bar graph

It would be correct to use a histogram to graph the time children spent playing with other children from data collected in a children's treatment center

True

False

For the scores shown in the stem and leaf display, what is the lowest score in the distribution?

Any frequency distribution is suitable for a stem and leaf display

True

False - a stem and leaf display is a simple alternative for a grouped frequency distribution

A score of 54 is displayed as a 5 (stem) and 4 (leaf) in a steam and leaf display

True

False

A sample of n = 12 scores has a mean of M = 8. What is the value of ΣX for this sample?

1.5

A sample of n = 7 scores has M = 5. All of the scores are doubled. What is the new mean?

More information is needed

It is possible for more than 50% of the scores ins a distribution to have values above the mean

True

False

It is possible for more than 50% of the scores in a distribution to have values above the median

True

False - median is exactly half

A distribution of scores shows the mean = 31 and the median = 43. This distribution is probably _____.

Positively skewed

Negatively skewed

Bimodal

Open-ended

The mean uses all of the scores in the data, so it is the best measure of central tendency for skewed data

True

False - mean moves towards the tail so it may not be representative of the true middle

If the mean and median have the same values, the distribution is probably symmetrical

True

False

The computational and definitional formulas for SS sometimes give different results

True

False - computational formula is just an algebraic rearrangement of the definitional formula, results are identical

If all the scores in the data set are the same, the standard deviation is equal to 1

True

False - 0

The standard deviation measures the _____.

Sum of the squared deviation scores

Standard distance of a score from the mean

Average difference of a score from the mean

Average squared distance of a score from the mean

The standard deviation is the distance from the mean to the farthest point on the distribution curve

True

False - extends from the mean approximately halfway to the most extreme score

A population has μ = 6 and σ = 2. Each score is multiplied by 10. What is the shape of the resulting distribution?

μ = 60 and σ = 2

μ = 6 and σ = 20

μ = 60 and σ = 20

μ = 6 and σ = 5

A biased statistic has been influenced by researcher error

True

False - bias refers to the systematic effect of using sample data to estimate a population parameter

On average, an unbiased sample statistics has the same value as the population parameter

True

False

A z-score of z = +1.00 indicates a position in a distribution _____.

Above the mean by 1 point

Above the mean by a distance equal to 1 standard deviation

Below the mean by 1 point

Below the mean by a distance equal to 1 standard deviation

A score close to the mean has a z-score close to 1

True

False - close to the mean = close to 0

For a population with μ = 50 and σ = 10, what is the X value corresponding to z = 0.4?

50.4

10.4

If μ = 40 and 50 corresponds to z = +2.00, then σ = 10 points.

True

False - If z = +2, then 2σ = 10, so σ = 5

If σ = 20, a score above the mean by 10 points will have z = 1.00.

True

False - If σ = 20, then z = 10/20 = 0.5

A score of X = 59 comes from a distribution with μ = 63 and σ = 8. This distribution is standardized to a new distribution with μ = 50 and σ = 10. What is the new value of the original score?

Last week Andy had exams in chemistry and in Spanish. On the chemistry exam, the mean was µ = 30 with σ = 5, and Andy had a score of X = 45. On the Spanish exam, the mean was µ = 60 with σ = 6, and Andy had a score of X = 65. For which class should Andy expect the better grade?

Chemistry

Spanish

There is not enough information to know

Transforming an entire distribution of scores into z-scores will not change the shape of the distribution.

True

False

If a sample of n = 10 scores is transformed into z-scores, there will be five positive z-scores and five negative z-scores.

True

False - number of z-scores above/below the mean with be exactly the same as the number of original scores above/below the mean

A deck of 52 cards contains 12 royalty cards. If you randomly select a card from the deck, what is the probability of obtaining a royalty card?

P = 1/52

P = 12/52

P= 3/52

P = 4/52

Choosing random individuals who walk by you yields a random sample.

True

False - not all individuals walk by, so not all have an equal chance of being selected for the sample

Probability predicts what kind of population is likely to be obtained.

True

False - the population is given; probability predicts what a sample is likely to be like

Find the proportion of the normal curve that corresponds to z > 1.50.

P = 0.9332

P = 0.5000

P = 0.4332

P = 0.0668

For any negative z-score, the tail will be on the right-hand side.

True

False - negative z-scores the tail will always be on the left side

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Stats Midterm Practice Test

Stats Midterm Practice Test

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